The next big “Learning Modular Synthesis” project is Eurorack Expansion. The idea behind it is that you already have a semi-modular synth or a small modular system, and now you’re wondering what to add next. As the saying goes, you need to walk before you can run. I’ve built up a core set of deceptively boring yet essential modules that will make it easier to interface your core system with the fun new modules you’re dying to try out.

In this installment I discuss updates to the Expert Sleepers Disting and ES-8, the introduction of the Five12 Vector Sequencer (hardware cousin of their Numerology sequencing software), and share conversations with Dave Rossum about design challenges in his new Morpheus filter and upcoming Assimil8or sample player.

Many semi-modular synths have just one VCO. They usually feature a square wave with pulse width animation, but if you want to use the sawtooth wave instead, the sound can be rather static. A common addition is a second oscillator; an interesting alternative is a “waveform animator.”

The thought process that went into building a compact yet comprehensive starting modular synth system for my Learn Modular Synthesis course that covered a wide range of both East and West Coast techniques.

Different oscillators and MIDI to CV converters may have varying ideas of what voltage a given note produces, and what pitch should you hear as a result. If there is a difference, in most cases it can be dialed out with a pitch knob or transpose switch. However, there are occasions when you need the assistance of an additional module to settle these disagreements.